In a trip full of highlights, Yellowstone is pretty close to the top of the list. (Sorry, world’s largest ball of twine! I’ll post about that later.)
Yellowstone is the country’s oldest national park. President Grant established it in a law dated March 1, 1872. It is huge–larger than the state of Rhode Island—and sits on an active volcanic area, although the last volcanic eruption happened about 70,000 years ago.

According to Wikipedia, my go-to source, there are over 10,000 geysers, hot springs, mudpots (acidic pools of boiling mud), and fumaroles (gas-emitting vents) in the park. On average, 465 geysers are active each year, but the formations are changing constantly, with features falling dormant, reawakening, or changing shape. Underlying these features is a massive hydrothermal system heated by magma that lies several miles below the earth’s surface.
Early explorers used to launder their clothes by throwing them into active geysers which would erupt and eject the clothes, boiled clean. Unfortunately, as the tourist trade grew, word of this spread, and people began throwing in socks, handkerchiefs, coins (for good luck), rocks, and other trash into the geysers, in the hopes of seeing them get blown back out of the vent holes. In some cases, the tourists permanently clogged the geysers. The Atlas Obscura notes:
According to The Geysers of Yellowstone, in 1950, [the geyser] Morning Glory was artificially induced to erupt in an effort to clean the trashed pond. The result is said to have blown out all sorts of items including bottles, cans, underwear, 76 handkerchiefs, and $86.27 in pennies.
As late as 2014, someone crashed their drone into a geyser, and there still are some tourists throwing trash into the geysers. The world is full of stupid people.
The temperature of the hot springs can reach 198° F at the surface, and is even hotter below, and the water can be highly acidic as well. Visitors are warned to stay on the paths and away from the water pools, for good reason. In 2016, a 23-year-old tourist, Colin Scott, decided to take a dip in one of the pools. As it was reported,
Scott found a pool and reached down to check the temperature, when he unfortunately slipped and fell into the hot and acidic pool. His body (and wallet and flip flops) was found floating in the pool later that day by park officials, though they were unable to retrieve it at the time due to it being out of reach, and a thunderstorm that developed and prevented them from continuing the job. The next day when they returned, there was nothing of the man left.
The body had literally boiled and dissolved away. Remember: obey the rules in national parks.
This first set of photos is from Yellowstone Lake, a caldera formed by a volcanic eruption approximately 640,000 years ago.



The main attraction is Old Faithful, on the left, which—while not the most impressive geyser in the park—is the most reliable: the Park Service can time the eruptions accurately, and they happen frequently. We also came upon the Daisy Geyser, seen on the right, just as it was about to erupt. (The estimated eruption times are posted online.)
There is much more to see, including the Grand Prismatic Spring, whose rings of color are created by microbial mats whose color depends on the amount of chlorophyll they contain.



Also, critters:




Next: more Yellowstone.




































































